&2 HOLLAND : MICA DEPOSITS OF INDIA. 



The saving effected would not be due merely to reduction of 

 labour. The miners, working blindly at the bottom of a ccecal hole, 

 damage large quantities of mica, more, very much more, than the mana- 

 ger appeared to suspect, whilst by tackling the pegmatite-sheet with 

 systematic over-hand stoping from the adit described, such damage to 

 the mica " books" would be reduced to a minimum. Fig. 17 is apian 

 of the hill showing how the position of the outcrop of the pegmatite 

 might have been traced with merely the knowledge of its angle of dip 

 and the position of the outcrop at the summit C. As at present 

 worked the whole of the materials are brought out of the opening at C, 

 whilst mining is going on at a point below ground corresponding to M 

 in the plan. The instance referred to is a mine where by chance the 

 contrast between the actual practice and the ideal method is unusually 

 pronounced, and the surface features are not always so convenient for 

 making a drive without the preliminary expense of a vertical shaft and 

 cross-cut. In a level country such operations would of course neces- 

 sitate the outlay of capital, with the attendant risk of the pegmatite 

 proving less remunerative than indicated by the preliminary prospecting 

 operations. Such a risk can, as a rule, be borne only by a company 

 whilst hitherto mica-mining in Bengal has been undertaken by indivi- 

 duals with, from a mining point of view, very limited resources. At 

 present a mine is only continued as long as it pays from month to month, 

 and this expensive system is preferred to the risks of a more complete 

 organization. As already stated, such a system of work is satisfactory 

 as long as there is an abundance of material near the surface, little 

 competition for land, no capital available, and the miner ignorant of the 

 structural characters of the pegmatite-sheets. But the time for the 

 casual native method is past, and an economical system should be 

 insisted on for the good of the mine-owners, as well as for the purpose 

 of- making the most of the natural resources of the country, which, 

 as explained on an earlier page (p. 11), are necessarily limited. 



Nellore. — The system of working mica in wide, open quarries, as 

 practised in the Nellore district, suggested itself on account of the level 

 nature of the surface, and the occurrence of the pegmatite in large 

 ( 72 ) 



